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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Using a regional numerical weather prediction model for GNSS positioning over Brazil

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Author(s):
Marra Alves, Daniele Barroca ; Sapucci, Luiz Fernando ; Marques, Haroldo Antonio ; de Souza, Eniuce Menezes ; Ferreira Gouveia, Tayna Aparecida ; Magario, Jackes Akira
Total Authors: 6
Document type: Journal article
Source: GPS SOLUTIONS; v. 20, n. 4, p. 677-685, OCT 2016.
Web of Science Citations: 4
Abstract

The global navigation satellite system (GNSS) can provide centimeter positioning accuracy at low costs. However, in order to obtain the desired high accuracy, it is necessary to use high-quality atmospheric models. We focus on the troposphere, which is an important topic of research in Brazil where the tropospheric characteristics are unique, both spatially and temporally. There are dry regions, which lie mainly in the central part of the country. However, the most interesting area for the investigation of tropospheric models is the wet region which is located in the Amazon forest. This region substantially affects the variability of humidity over other regions of Brazil. It provides a large quantity of water vapor through the humidity convergence zone, especially for the southeast region. The interconnection and large fluxes of water vapor can generate serious deficiencies in tropospheric modeling. The CPTEC/INPE (Center for Weather Forecasting and Climate Studies/Brazilian Institute for Space Research) has been providing since July 2012 a numerical weather prediction (NWP) model for South America, known as Eta. It has yield excellent results in weather prediction but has not been used in GNSS positioning. This NWP model was evaluated in precise point positioning (PPP) and network-based positioning. Concerning PPP, the best positioning results were obtained for the station SAGA, located in Amazon region. Using the NWP model, the 3D RMS are less than 10 cm for all 24 h of data, whereas the values reach approximately 60 cm for the Hopfield model. For network-based positioning, the best results were obtained mainly when the tropospheric characteristics are critical, in which case an improvement of up to 7.2 % was obtained in 3D RMS using NWP models. (AU)

FAPESP's process: 12/19906-7 - Robust evaluation of atmospheric modeling impact in Network-Based positioning
Grantee:Daniele Barroca Marra Alves
Support type: Regular Research Grants